Herbicidal 12-substituted 12H-dibenzo(D,G)(1,3)dioxocin-6-carboxylic acids

ABSTRACT

Dibenzo[d,g][1,3]dioxocin-6-carboxylic acids substituted by methyl or ethyl or a moiety --CH 2  CH 2  -- at the 12-position and optionally substituted at other positions, such as methyl 4&#39;-chlorospiro(cyclopropane-1,12&#39;(12&#39;H)-dibenzo[d,g][1,3]dioxocin)-6&#39;-carboxylic acid, and their agriculturally acceptable esters, amides, and salts are useful for the control of undesirable vegetation. The 1,1-diarylcyclopropane intermediates required for the spirocyclopropane compounds can be prepared from appropriately substituted 1,1-diarylethene procursors by reaction with phenylthiomethyl lithium reagent.

BACKGROUND OF THE INVENTION

The present invention relates to certaindibenzo[d,g][1,3]dioxocin-6-carboxylic acids substituted in the12-position and, optionally, in other positions and to related compoundsthat are convertible to substituteddibenzo[d,g][1,3]dioxocin-6-carboxylic acids in the environment or inplants and to the use of these compounds as herbicides.

Certain substituted dibenzo[d,g][1,3]dioxocin-6-carboxylic acids thatare unsubstituted at the 12-position and certain of their correspondingesters and amides are known in the art and are reported to possessspecific pharmacological utilities. See, for example, U.S. Pat. Nos.3,931,173 and 3,553,234 and J. Medicinal Chemistry, 15, 1273-1278(1972). Little else is known about this class of compounds.

The production of quality food and fiber is highly dependent on theavailability of safe and effective herbicides to control unwantedvegetation. New compounds that are useful in this regard arecontinuously sought and when found, highly prized.

SUMMARY OF THE INVENTION

It has now been found that substituteddibenzo[d,g][1,3]dioxocin-6-carboxylic acids having hydrocarbylsubstitution at the 12-position carbon atom and the salts, esters andamides derived from these acids as well as other related compounds whichare chemically or biochemically converted to these acids in theenvironment or within plants are useful herbicides.

In particular, substituted dibenzo[d,g][1,3]-dioxocin-6-carboxylic acidcompounds of Formula I ##STR1## wherein R¹ and R² each, independentlyrepresent hydrogen, methyl, or ethyl, with the proviso that not morethan one of R¹ and R² represents hydrogen, or R¹ and R² togetherrepresent the fragment --CH₂ CH₂ --:

R³ represents H or CH₃ ; and

X, X', Y, Y', Z, and Z' each, independently represent H, F, Cl, Br, I,CN, NO₂,CO₂ H, NH₂, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenoxy, C₁ -C₄alkylthio, phenylthio, C₁ -C₄ mono- or dialkylamino, (C₁ -C₃alkyl)carbonyl, or phenylcarbonyl, wherein each alkyl, alkoxy, andalkylthio group is optionally substituted with one or more compatiblegroups selected from C₁ -C₄ alkoxy, C₁ -C₄ alkylthio, F, Cl, Br, CN, andphenyl and wherein each phenyl group is optionally substituted with upto 3 groups selected from F, Cl, Br, CN, CF₃, C₁ -C₄ alkyl, and C₁ -C₄alkoxy:

and the agriculturally acceptable salt, esters and amides thereof; andobtainable compounds which are oxidizable or hydrolyzable in plants orthe environment to a dibenzo[d,g][1,3]dioxocin-6-carboxylic acidcompound of Formula I are useful for the control of undesirablevegetation.

Compositions containing an herbicidally effective amount of a compoundof Formula I in admixture with an agriculturally acceptable adjuvant orcarrier are usually applied to the undesirable vegetation or the locusthereof in either preemergence or postemergence operations.

The compounds of Formula I wherein R¹ and R² together represent --CH₂CH₂ --(the moiety --CR¹ R² --represents cyclopropylidine) are agenerally preferred class. Compounds of Formula I wherein R³ representshydrogen are also often preferred. Preferred ring substituents includeH, F, Cl, Br, CH₃, OCH₃, SCH₃, CF₃, and OC₆ H₅. It is often preferred toemploy a compound of Formula I wherein at least one of X and X'represents a designated substituent other than hydrogen.

The invention further embraces a method of preparing a compound ofFormula XII ##STR2## wherein R¹ and R² together represent the fragment--CH₂ CH₂ --;

each R⁴ independently represents C₁ -C₄ alkyl optionally substitutedwith 1 or 2 C₁ -C₄ alkoxy groups; and

X, X', Y, Y', Z, and Z' each, independently represent H, F, Cl, Br, I,CN, NO₂, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenoxy, C₁ -C₄ alkylthio,phenylthio, or C₁ -C₄ dialkylamino, wherein each alkyl, alkoxy, andalkylthio group is optionally substituted with one or more compatiblegroups selected from C₁ -C₄ alkoxy, C₁ -C₄ alkylthio, F, Cl, Br, CN, andphenyl and wherein each phenyl group is optionally substituted with upto 3 groups selected from F, Cl, Br, CN, CF₃, C₁ -C₄ alkyl, and C₁ -C₄alkoxy

which comprises contacting thioanisole with a C₁ -C₈ alkyl lithiumreagent and an aliphatic tertiary amine in a compatible solvent to forma phenylthiomethyl lithium reagent and subsequently contacting saidphenylthiomethyl lithium reagent with a compound of Formula XI ##STR3##wherein X, X', Y, Y', Z, and Z' each, independently represent H, F, Cl,Br, I, CN, NO₂, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenoxy, C₁ -C₄ alkylthio,phenylthio, or C₁ -C₄ dialkylamino, wherein each alkyl, alkoxy, andalkylthio group is optionally substituted with one or more compatiblegroups selected from C₁ -C₄ alkoxy, C₁ -C₄ alkylthio, F, Cl, Br, CN, andphenyl and wherein each phenyl group is optionally substituted with upto 3 groups selected from F, Cl, Br, CN, CF₃, C₁ -C₄ alkyl, and C₁ -C₄alkoxy under conditions conducive to the reaction.

DETAILED DESCRIPTION OF THE INVENTION

The 12-substituted 12H-dibenzo[d,g][1,3]-dioxocin-6-carboxylic acidcompounds of Formula I wherein R¹, R², R³, X, X', Y, Y', Z, and Z' areselected from among the substituents designated in the Summary of theInvention as well as the agriculturally acceptable salts, esters, andamides derived from these acids and all obtainable compounds that areconverted to these acids when applied as herbicides are compounds withinthe scope of the invention. The subject acids are characterized by thepresence of a 12H-dibenzo[d,g][1,3]dioxocin ring system, a carboxylicacid moiety in the 6-position, the presence of at least one hydrocarbonsubstituent in the 12-position (which substituents may form a carbocyclewith the 12-position carbon atom), and the absence of substituents otherthan hydrogen at the 2- and 10-positions.

The compounds of Formula I possess an asymmetric carbon atom at the6-position and, whenever R² and R³ are different, also possess a secondasymmetric carbon atom at the 12-position. These compounds, therefore,can exist in several chiral and geometric isomeric forms. Each possiblesuch isomer is described by Formula I and the present invention relatesto each of these isomers independently as well as to all mixturesthereof.

The terms alkyl, alkenyl, alkoxy, and alkylthio as used herein includestraight chain and branched chain isomers. Thus, typical alkyl groupsare methyl, ethyl, 1-methylethyl, 1,1-dimethylethyl, propyl,2-methylpropyl, 1-methylpropyl, and butyl. Compatible substituents aresubstituents that are chemically and sterically capable of existing inthe designated positions at the same time.

Agriculturally acceptable salts, esters and amides are those salts,esters and amides of the carboxylic acid group(s) of Formula I whichhave a cation, OR, NH₂, NHR, or NRR moiety that is not itselfsignificantly herbicidal to any crop being treated and not significantlydeleterious to the applicator, the environment, or the ultimate user ofany crop being treated.

Suitable cations include, for example, those derived from alkali oralkaline earth metals and those derived from ammonia and amines.Preferred cations include sodium, potassium, magnesium, and aminiumcations of the formula

    R.sup.5 R.sup.6 R.sup.7 NH⊕

wherein R⁵, R⁶, and R⁷ each, independently represents hydrogen or C₁-C₁₂ alkyl, C₃ -C₁₂ cycloalkyl, or C₃ -C₁₂ alkenyl, each of which isoptionally substituted by one or more hydroxy, C₁ -C₈ alkoxy, C₁ -C₈alkylthio or phenyl groups, provided that R⁵, R⁶, and R⁷ are stericallycompatible. Additionally, any two of R⁵, R⁶, and R⁷ together mayrepresent an aliphatic difunctional moiety containing 1 to 12 carbonatoms and up to two oxygen or sulfur atoms. Salts of the compounds ofFormula I can be prepared by treatment of compounds of Formula I with ametal hydroxide, such as sodium hydroxide, potassium hydroxide, ormagnesium hydroxide, or an amine, such as ammonia, triethylamine,dimethylamine, hydroxyethylamine, trisallylamine, 2-butoxyethylamine,morpholine, cyclododecylamine, or benzylamine.

Suitable esters and amides include those wherein each R independentlyrepresents C₁ -C₈ alkyl or C₃ -C₈ alkenyl, each substituted with up to 3compatible groups selected from C₁ -C₄ alkoxy, F, Cl, Br, and phenyl, orphenyl optionally substituted with up to 3 groups selected from F, Cl,Br, CH₃, or CF₃. C₁ -C₄ Alkyl esters are generally preferred and methyland butyl esters are often specifically preferred.

The nature of the substituents R¹, R², R³, X, X', Y, Y', Z, and Z'within the described limits does not appear to be critical to thegeneral utility of the compounds, but it is a factor in determining thedegree of herbicidal activity and the selectivity of the herbicidalaction of these compounds. Consequently, some of the compounds arepreferred. With respect to R¹ and R², compounds having R¹ and R²together represent the moiety --CH₂ CH₂ --: i.e., compounds wherein thecarbon atom at the 12-position is part of a cyclopropylidine moiety, area preferred sub-set. These compounds are generally termedspiro(cyclo-propane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylates.Other preferred R¹ and R² substituents include methyl. Hydrogen is thepreferred R³ substituent. With respect to the ring substituents X, X',Y, Y', Z, and Z', compounds wherein each of these substituentsrepresents hydrogen are often preferred. Compounds wherein at least oneof X and X' represents a designated substituent other than hydrogen arealso often preferred. Of the substituents designated for X, X', Y, Y',Z, and Z', the following are often preferred: H, F, Cl, Br, CH₃, OCH₃,SCH₃, CF₃, and OC₆ H₅.

The compounds of Table I are illustrative of the compounds of theinvention.

    __________________________________________________________________________     ##STR4##                                                                     SUBSTITUTED DIBENZO[D,G][1,3]DIOXOCIN-6-CARBOXYLIC ACIDS                      AND ACID FUNCTION DERIVATIVES                                                                                                            Melt-                                                                         ing                Cpd.                                                                             R.sup.1 /R.sup.2                                        Point,             No.                                                                              (isomer)                                                                            R.sup.3                                                                          X      Y   Z    X'     Y'     Z'    Acid Function                                                                            °C.         __________________________________________________________________________    1  CH.sub.3 /H                                                                         H  Cl     H   H    H      H      H     methyl ester                                                                             124-136               (3.7:1)                                                                    2  CH.sub.3 /H                                                                         H  Cl     H   H    H      H      H     methyl ester                                                                             144-145               (trans)                                                                    3  CH.sub.3 /H                                                                         H  H      H   H    H      H      H     methyl ester                                                                             146-147               (cis)                                                                      4  CH.sub.3 /H                                                                         H  H      H   H    H      H      H     methyl ester                                                                             solid                 (1:1)                                                                      5  CH.sub.3 /H                                                                         CH.sub.3                                                                         CF.sub.3                                                                             H   F    Br     H      Br    NHC.sub.3 H.sub.7 amide       6  CH.sub.3 /H                                                                         H  Cl     Cl  H    Cl     Cl     H     CH.sub.2 CH.sub.2                                                             OCH.sub.3 ester               7  CH.sub.3 /CH.sub.3                                                                  H  H      H   H    H      H      H     acid       <50                8  CH.sub.3 /CH.sub.3                                                                  H  H      H   H    H      H      H     methyl ester                                                                             91-92              9  CH.sub.3 /CH.sub.3                                                                  H  CH.sub.3                                                                             H   CN   CH.sub.3                                                                             H      CN    sodium salt                   10 CH.sub.3 /CH.sub.3                                                                  H  I      SCH.sub.3                                                                         H    H      NO.sub.2                                                                             H     C.sub.4 H.sub.9 ester         11 CH.sub.3 /CH.sub.3                                                                  CH.sub.3                                                                         CH.sub.3                                                                             Cl  Cl   CH.sub.3                                                                             Cl     Cl    ammonium salt                 12 CH.sub.3 /CH.sub.3                                                                  CH.sub.3                                                                         SCH(CH.sub.3).sub.2                                                                  H   OCH.sub.3                                                                          F      H      CO.sub.2 C.sub.3 H.sub.5                                                            CH.sub.2 CClCCl.sub.2                                                         ester                         13 CH.sub.3 /C.sub.2 H.sub.5                                                           H  H      H   H    H      H      H     acid       123-124               (95:5)                                                                     14 CH.sub.3 /C.sub.2 H.sub.5                                                           H  H      H   H    H      H      H     acid       80-85                 (1:1)                                                                      15 CH.sub.3 /C.sub.2 H.sub.5                                                           CH.sub.3                                                                         OCF.sub.2 CFClH                                                                      H   NHCH.sub.3                                                                         OCH.sub.3                                                                            CO.sub.2 CH.sub.2                                                                    CH.sub.3                                                                            CO.sub.2 CH.sub.2                                                             CH(OCH.sub.3)                                                    CH(OCH.sub.3)                                                                              CH.sub.2 OCH.sub.3 ester                                         CH.sub.2 OCH.sub.3                         16 C.sub.2 H.sub.5 /H                                                                  H  H      H   H    H      H      H     acid       142-145               (1:1)                                                                      17 C.sub.2 H.sub.5 /H                                                                  H  H      H   H    H      H      H     methyl ester                                                                             134.5-                (1:1)                                                   135.5              18 C.sub.2 H.sub.5 /C.sub.2 H.sub.5                                                    H  NH.sub.2                                                                             CN  H    CH.sub.3                                                                             H      OCF.sub.2 H                                                                         morphoinium salt              19 (CH.sub.2).sub.2                                                                    H  H      H   H    H      H      H     acid       142.5-145          20 (CH.sub.2).sub.2                                                                    H  H      H   H    H      H      H     methyl ester                                                                             132-134            21 (CH.sub.2).sub.2                                                                    H  H      H   H    H      H      H     ethyl ester                                                                              114-115            22  (CH.sub.2).sub.2                                                                   H  H      H   H    H      H      H     isopropyl                                                                                84-87              23 (CH.sub.2).sub.2                                                                    H  H      H   H    H      H      H     NHOH amide 127-135                                                                       (d)                24 (CH.sub.2).sub.2                                                                    H  H      OCH.sub.3                                                                         H    H      H      H     acid       137-139            25 (CH.sub.2).sub.2                                                                    H  H      OCH.sub.3                                                                         H    H      H      H     methyl ester                                                                             129-131            26 (CH.sub.2).sub.2                                                                    H  OCH.sub.3                                                                            H   H    H      H      H     methyl ester                  27 (CH.sub.2).sub.2                                                                    H  OCH.sub.3                                                                            OCH.sub.3                                                                         H    H      H      H     methyl ester                  28 (CH.sub.2).sub.2                                                                    H  CH.sub.3                                                                             H   H    H      H      H     acid       192-193            29 (CH.sub.2).sub.2                                                                    H  CH.sub.3                                                                             H   H    H      H      H     methyl ester                                                                             98-99              30 (CH.sub.2).sub.2                                                                    H  Cl     H   H    H      H      H     acid       154-158            31 (CH.sub.2).sub.2                                                                    H  Cl     H   H    H      H      H     methyl ester                                                                             105-111            32 (CH.sub.2).sub.2                                                                    H  CON(CH.sub.3).sub. 2                                                                 H   H    H      H      H     acid       112-118            33 (CH.sub.2).sub.2                                                                    H  CON(CH.sub.3).sub.2                                                                  H   H    H      H      H     methyl ester                                                                             131-134            34 (CH.sub.2).sub.2                                                                    H  COC.sub.6 H.sub.5                                                                    H   H    H      H      H     acid       183-186            35 (CH.sub.2).sub.2                                                                    H  COC.sub.6 H.sub.5                                                                    H   H    H      H      H     methyl ester                                                                             135-139            36 (CH.sub.2).sub.2                                                                    CH.sub.3                                                                         N(CH.sub.3).sub.2                                                                    H   Cl   H      H      COCF.sub.3                                                                          C.sub.8 H.sub.17 ester        37 (CH.sub.2).sub.2                                                                    CH.sub.3                                                                         NO.sub.2                                                                             OC.sub.2 H.sub.5                                                                  Cl   CON(CH.sub.3).sub.2                                                                  CN     NH.sub.2                                                                            N(CH.sub.3).sub.2 amide       38 (CH.sub.2).sub.2                                                                    H  CO.sub.2 CH.sub.4 H.sub.9                                                            F   CN   H      CF.sub.3                                                                             S(CH.sub.2).sub.2 CN                                                                (C.sub.2 H.sub.5).sub.3                                                       NH.sup.+  salt                39 (CH.sub.2).sub.2                                                                    H  H      Br  C.sub.2 H.sub.5                                                                    CH(CH.sub.3).sub.2                                                                   F      H     CH.sub.3 (CH.sub.2).sub.7                                                     O                                                                             CH.sub.2 CH.sub.2                                                             NH.sub.3.sup.+  salt          40 (CH.sub.2).sub.2                                                                    H  H      COC.sub.6 -                                                                       H    H      H      NO.sub.2                                                                            potassium salt                                   H.sub.4 Cl                                                 41 (CH.sub.2).sub.2                                                                    CH.sub.3                                                                         CF.sub.3                                                                             H   Cl   CF.sub.3                                                                             H      Cl    NH.sub.2 amide                42 (CH.sub.2).sub.2                                                                    H  OC.sub.4 H.sub.9                                                                     CH.sub.3                                                                          H    OC.sub.4 H.sub.9                                                                     CH.sub.3                                                                             H     NHCH.sub.2 CO.sub.2                                                           CH.sub.3                                                                      amide                         43 (CH.sub.2).sub.2                                                                    H  H      CH.sub.3                                                                          H    H      H      H     acid                          44 (CH.sub.2).sub.2                                                                    H  H      CH.sub.3                                                                          H    H      H      H     methyl ester                  __________________________________________________________________________

Compounds which are obtainable employing the teachings herein, theteachings and suggestions of the prior art, and ordinary skill in theart and which degrade in the environment or within plants to a compoundof Formula I will have utilities similar to the compounds of Formula Iand the use of such compounds is within the scope of the presentinvention. Many such compounds can be envisioned. Thus, those compoundswhich are readily oxidized and/or hydrolyzed in the environment orwithin a plant system to a compound of Formula I, such as, for example,the 6-hydroxymethyl, 6-aminomethyl, 6-formyl, 6-(2-carboxyethyl),6-(5-chloro-2-pentenyl), 6-cyano, 6-(2-dioxolanyl), and many otherderivatives have approximately the same utility as the compound to whichthey degrade. The art is replete with other functional groups which aredegradable to carboxylic acids, and accordingly, when any of thesefunctional groups is present in place of the CO₂ H moiety in the6-position of a compound of Formula I, a useful herbicide is obtained.

The compounds of the present invention can be prepared in a number ofways. The most general method involves the condensation of a bisphenolcompound of Formula II, wherein X, X', Y, Y', Z, Z', R¹ and R² are asdefined in the Summary of the Invention, with a 2,2-dihaloalkanoic acidof Formula III, wherein R³ represents hydrogen or methyl and G denoteschloro or bromo; or with an ester or amide of such a 2,2-dihaloalkanoicacid. Dichloroacetic acid is preferred. ##STR5## The process can becarried out essentially as described for related compounds in U.S. Pat.Nos. 3,553,234 and 3,931,173, and J. Med. Chem., 15, 1273-1278 (1972),the appropriate portions of which are hereby incorporated by reference.It is often convenient to reflux a mixture of a compound of Formula IIand a compound of Formula III (or an ester or amide thereof) in asolvent with a catalytic amount of potassium iodide for a few days.2-Propanol is a preferred solvent.

It is generally preferred to do the condensation with an acid of FormulaIII and, if desired, to subsequently convert the compound of Formula I(acid form) obtained to an agriculturally acceptable ester or amideusing standard methods well known to those of ordinary skill in the art.It is sometimes preferred to choose the acid, ester or amide of acompound of Formula III which corresponds to a desired acid, ester oramide of the compound of Formula I to be prepared. In this way thesubsequent interconversion or these functionalities to obtain thedesired derivative can be avoided.

Alternately, the cyclization can be accomplished by condensation of abisphenol of Formula II with diethyl dibromomalonate and base. Thedesired compound of Formula I can be obtained after hydrolysis anddecarboxylation of the product prepared, using standard conditions forsuch reactions. This condensation requires less drastic conditions thanthe usual method and is valuable for compounds having substituents thatare unstable in base, such as trifluoromethyl.

A few compounds of Formula II, wherein R¹ and/or R² represent methyl orethyl and X, X', Y, Y', Z, and Z' are as defined in the Summary of theInvention, are known in the art. These and other compounds of Formula IIcan be prepared in a variety of ways. For example, compounds of FormulaII wherein one of R¹ and R² represents methyl or ethyl and the otherrepresents hydrogen can be prepared by condensing an appropriatecompound of Formula IV wherein R" represents methyl or methoxymethyl andW represents hydrogen or bromo with an appropriate compound of Formula Vwherein R' represents methyl, methoxymethyl, or hydrogen and R"'represents methyl or ethyl with an alkyl lithium compound, such as butyllithium, and subsequently reducing and dealkylating thebis(substituted-phenyl)methanol compound of Formula VI obtained. R" isoften preferably methoxymethyl and R' is often preferably methyl. W isusually preferably hydrogen unless X is hydrogen or bromo in which casebromo is usually preferable. The condensation can be carried out byfirst lithiating the compound of Formula IV with the alkyl lithium atabout 0° C. in an ether type solvent, such as tetrahydrofuran, in thepresence of a complexing agent, such as tetramethylethylenediamine, andthen allowing the lithium compound formed to react with the substitutedacetyl or propionyl compound of Formula V under similar conditions. Thecompound of Formula VI formed can be recovered by adding a saturatedaqueous solution of ammonium chloride and extracting with ether.##STR6##

A variety of methods exist for reducing and dealkylating the compoundsof Formula VI to compounds of Formula II. It has been found convenientto first reduce the 1,1-bis(substituted-phenyl)alkanol to thecorresponding 1,1-bis(substituted-phenyl)alkane with a trialkylsilaneand trifluoroacetic acid. Typically, the compound of Formula VI istreated with these reagents in a solvent, such as methylene chloride, atambient temperature. The product can be recovered by quenching thereaction mixture with saturated aqueous sodium bicarbonate andextracting with ether. The 1,1-bis(substituted-phenyl)alkane thusobtained can be dealkylated (have the R' and R" alkyl groups removed) bymost general methods for such reactions. Sometimes, methoxymethyl groupsare removed incidentally in the trialkylsilane reduction process.Typically, methoxymethyl groups can be removed by allowing the compoundsto react with p-toluenesulfonic acid in refluxing methanol or bytreatment with bromodiethylborane. Methyl groups can be removed byreaction with boron tribromide or bromodimethylborane. Typically, themethoxy containing compound is combined with boron tribromide orbromodimethylborane in a solvent, such as methylene chloride, at ambienttemperature to effect the reaction. The resulting compound of Formula IIcan be recovered by conventional means, such as extraction into aqueousalkali and then adding acid. A large number of the starting materialcompounds of Formulas IV and V are known in the art or can be made bymethods known in the art. Ether compounds of Formula IV are readilyprepared from the corresponding phenols of Formula VII by conventionalmethods.

Alternately, many of the compounds of Formula II can be prepared bycondensation of a compound of Formula VII with a compound of FormulaVIII using a Grignard reagent, such as ethyl magnesium bromide, inexcess. Typically, the condensation is effected by combining thereagents in ether, replacing the ether with benzene after a shortperiod, and heating the latter mixture at reflux for several hours. Thecompound of Formula II is recovered by conventional techniques forGrignard reactions. A large number of the starting material compounds ofFormulas VII and VIII are known in the art or can be made by methodsknown in the art. ##STR7##

Other methods exist for the preparation of compounds of Formula II. Forexample, many dihydroxybenzophenones of Formula IX are known in the artor can be made by methods known in the art and many of these can beconverted to compounds of Formula II. ##STR8##

One method of preparation of compounds of Formula IX is by oxidation ofa compound of Formula VI wherein R"' represents hydrogen. Such compoundsof Formula VI can, in turn, be prepared in the same manner as compoundsof Formula VI wherein R"' represents methyl or ethyl by using a compoundof Formula V wherein the R"' moiety is replaced by hydrogen. Dipyridinechromic oxide (Collins' reagent) is one suitable oxidizing agent for thetransformation. In a typical procedure pyridine and chromic oxide arecombined at about 0° C. and then an appropriate compound of Formula VIis added and the mixture allowed to react at or below ambienttemperature for several hours. The desired product can be recovered byconventional means.

Compounds of Formula II wherein one of R¹ and R² represents methyl orethyl and the other represents hydrogen can be prepared from compoundsof Formula IX by alkylation with methyl or ethyl magnesium bromide inether under typical Grignard reaction conditions to obtain a compound ofFormula VI. The product can be recovered using typical Grignard reactionwork-up procedures. The compound of Formula VI can then be reduced anddealkyated as described here-in-above to obtain the desired compound ofFormula II.

Compounds of Formula II wherein both R¹ and R² represent methyl or ethylor together R¹ and R² represent the moiety --CH₂ CH₂ --can be preparedfrom compounds of Formula IX by first converting the compound of FormulaIX to a compound of Formula X ##STR9## This can be accomplished bytreating the compound of Formula IX with methyl magnesium bromide toobtain a 1,1-bis(substituted-phenyl)ethanol (compound of Formula VIwherein R"' represents methyl) as described above and then dehydratingthis compound. Compounds of Formula VI obtained by other means are, ofcourse, equally employed. The dehydration can be carried out, forexample, by heating the compound of Formula VI in acetic anhydridecontaining a catalytic amount of sulfuric acid and recovering theproduct of Formula X by conventional means. An ethylidene analog (CH₂═replaced by CH₃ CH═) can be prepared by substituting ethyl magnesiumbromide for methyl magnesium bromide in the procedure. The methodproceeds at least equally as well when the dimethyl ether of a compoundof Formula IX is employed as the substrate and the dimethyl ether of thecorresponding compound of Formula X is obtained. Alternately, the alkylether derivatives of compounds of Formula X can be prepared by treatmentof the dialkyl ether derivatives of compounds of Formula IX withmethyltriphenylphosphonium bromide and sodium hydride intetrahydrofuran, an application of the well-known Wittig reaction. Thedesired intermediates of Formula X can also be prepared by allowing abis(methoxymethyl) ether derivative of a compound of Formula IX to reactin tetrahydrofuran first with trimethylsilylmethyl lithium and then withpotassium t-butoxide to obtain a bis(methoxymethyl) ether derivative ofa compound of Formula X and subsequently removing the methoxymethylprotecting groups with a standard reagent, such as methanol containing acatalytic amount of p-toluenesulfonic acid. This is often a preferredmethod.

The dimethyl ether analogs of the compounds of Formulas IX and X can beprepared from compounds of Formulas IX and X, respectively, for example,by treatment with methyl iodide and a base under conditions well knownin the art. The bis(methoxymethyl) ether analogs can also be prepared byconventional procedures, which generally employ dimethoxymethane and anacid catalyst. Demethylation of the dimethyl ether analogs of compoundsof Formulas II, IX, and X and the like can be accomplished by treatmentwith boron tribromide, bromodimethylborane or any of the other suitablereagent known in the art. De(methoxymethylation) of thebis(methoxymethyl) ether analogs of these compounds can be accomplishedwith the same reagents as well as with milder reagents, such asbenzenesulfonic acid in methanol.

Compounds of Formula II wherein one of R¹ and R² represents ethyl andthe other represents methyl or ethyl can be prepared from compounds ofFormula X by treatment of the dimethyl ether derivatives of thesecompounds with methyl lithium and then methyl or ethyl bromide. Themethyl lithium is generally added to a solution of the reactant intetrahydrofuran and after a 1 to 4 hour period the alkyl iodide is addedslowly. The dimethyl ether analog of the desired compound of Formula Xcan be recovered by conventional means. It can be converted to acompound of Formula X by demethylation using standard methods.

Compounds of Formula XII ##STR10## wherein R¹ and R² together representthe moiety --CH₂ CH₂ --(the moiety bridging the two benzene rings is acyclopropylidine moiety) and wherein each R⁴ independently represents C₁-C₄ alkyl optionally substituted 1 or 2 C₁ -C₄ alkoxy groups and X, X',Y', Z, and Z' each, independently represent H, F, Cl, Br, I, CN, NO₂, C₁-C₄ alkyl, C₁ -C₄ alkoxy, phenoxy, C₁ -C₄ alkylthio, phenylthio, or C₁-C₄ dialkylamino, wherein each alkyl, alkoxy, and alkylthio group isoptionally substituted with one or more compatible groups selected fromC₁ -C₄ alkoxy, C₁ -C₄ alkylthio, F, Cl, Br, CN, and phenyl and whereineach phenyl group is optionally substituted with up to 3 groups selectedfrom F, Cl, Br, CN, CF₃, C₁ -C₄ alkyl, and C₁ -C₄ alkoxy can be preparedfrom a compound of Formula XI, ##STR11## wherein the substituents aredefined in the same way, by treatment with phenylthiomethyl lithium.

A solution of phenylthiomethyl lithium in a compatible solvent, such aspentane, decane or another aliphatic hydrocarbon solvent ortetrahydrofuran, dimethoxy-ethane, diethyl ether or another ether typesolvent, is generally first prepared by adding an alkyl lithium reagent,such as butyl lithium, to a solution of thioanisole (methylthiobenzene)and an aliphatic tertiary amine, such as 1,4-diazabicyclo[2,2,2]octane,in a compatible solvent. Approximately equimolar amounts of each of thereactants are employed although this is not critical. The mixture isgenerally cooled to around 0° C. and the reaction allowed to proceed attemperatures up to about 30° C. The reaction is generally complete inless than one hour. The phenylthiomethyl lithium reagent prepared isgenerally combined with an approximately equimolar or lesser amount of acompound of Formula XI in a compatible solvent. The combination can bemade over a wide range of temperatures and is often most convenientlycarried out at about ambient temperature. The mixture is then generallyheated to complete the conversion. Temperatures of about 30° C. to about100° C. or the reflux temperature of the mixture are typically employedand the reaction is generally complete within 24 hours after thetemperature is elevated. The desired product of Formula XII (a bisetherderivative of a compound of Formula II wherein R¹ and R² togetherrepresent the moiety --CH₂ CH₂ --) can be recovered by conventionalmeans. It is often readily recovered by quenching with water, separatingthe aqueous phase that forms, extracting the organic phase with morewater, distilling the organic phase under reduced pressure to remove thevolatile organics, and chromatographing the residue. Compounds ofFormula II wherein R¹ and R² together represent the moiety --CH₂ CH₂--can be obtained from the compounds prepared in the process describedabove by dealkyation using standard methods. A compatible solvent is onethat dissolves at least a small amount of each reactant and which ischemically inert in the system.

It is also possible to obtain compounds of Formula XII wherein R¹ and R²together represent the moiety --CH₂ CH₂ --from appropriate bisetherderivatives of the compounds of Formula IX by treatment with triethylphosphonoacetate and sodium hydride in an ether solvent, such asdimethoxyethane, followed by treatment of the intermediate obtained withlithium aluminum hydride in an ether solvent. The triethylphosphonoacetate and sodium hydride are generally first combined andallowed to react and then the bisether derivative of a compound ofFormula IX is added and the mixture heated for about a day. Anintermediate product can be recovered by adding water and isolating theorganic phase. This intermediate, in crude or purified form, is thengenerally added to lithium aluminum hydride in tetrahydrofuran and themixture heated at reflux for several hours. The expected product isrecovered by conventional means for such reactions. The procedure issimilar to that described in Organic Synthesis, Collective Volume V, pp509-510. The desired compound of Formula II is obtained by dealkylationof the ether substituents by conventional means.

The choice of a method to use in the preparation of the desired compoundof Formula II will depend on the availability of starting materials, thesensitivity of the substituents to the reaction conditions that will beemployed in subsequent reactions, and the possibility of isomerformation which would make recovery of the desired product difficult.Protecting groups, such as t-butyl and trimethylsilyl, can be employedin the process and subsequently removed as is known in the art.

It is not always necessary to prepare a compound of Formula II to obtainthe corresponding compound of Formula I. It is often possible anddesirable to prepare certain compounds of Formula I by converting onecompound of Formula I (or a related compound with a substituent patternnot covered by Formula I) prepared as described herein or obtained inanother manner to another compound of Formula I using conventionchemical methods. Thus, for example, a t-butyl group can be used as aprotecting group and removed by treatment with aluminum chloride, abromo or iodo substituent can be removed with a reducing agent orreplaced by other groups by nucleophilic displacement, such as withcuprous cyanide, a nitro group can be reduced to an amino group, atrialkylsilyl group can be replaced by bromo or iodo, and a methoxygroup can be converted to a hydroxy group with an alkanethiol and base.An hydroxy group can further be alkylated by known methods to alkoxygroups, including substituted alkoxy groups as defined in the Summary ofthe Invention. Such transformations are well known to those in the art.

It is further possible to prepare compounds of Formula I from compoundsof Formula IX by first condensing the latter with a compound of FormulaIII in the same manner employed in the reaction of compounds of FormulaII with compounds of Formula III and then appropriately modifying the12-oxo analog of the compound of Formula I obtained by the generalmethods described herein or otherwise known in the art.

Compounds of Formula I wherein R³ represents methyl are usually bestprepared by methylation of a compound of Formula I wherein R³ representshydrogen. In typical operations a compound of Formula I wherein Rrepresents hydrogen is added dropwise with stirring to a solution of analkyl lithium compound, such as butyl lithium, and diisopropylamine in asolvent, such as tetrahydrofuran, while cooling with dry-ice and acetoneto about -78° C. and after a few minutes adding excess methyl iodide.The 6-methyl compound can be recovered be conventional means, forexample, by adding dilute aqueous hydrochloric acid and then extractingwith ether.

The compounds of the present invention can be used directly asherbicides, but it is generally preferable to first prepare a herbicidalcomposition containing one or more of the compounds in combination withan agriculturally acceptable adjuvant or carrier. Suitable adjuvants orcarriers should not be phytotoxic to valuable crops, particularly at theconcentrations employed in applying the compositions for selective weedcontrol in the presence of crops, and should not react chemically withcompounds of Formula I or other composition ingredients. Such mixturescan be designed for application directly to plants or their locus or canbe concentrates or formulations which are normally diluted withadditional carriers and adjuvants before application. They can besolids, such as, for example, dusts, granules, water dispersiblegranules, or wettable powders, or liquids, such as, for example,emulsifiable concentrates, solutions, emulsions or suspensions.

Suitable agricultural adjuvants and carriers that are useful inpreparing the herbicidal mixtures of the invention are well known tothose skilled in the art.

Liquid carriers that can be employed include water, toluene, xylene,petroleum naphtha, crop oil, acetone, methyl ethyl ketone,cyclohexanone, trichloroethylene, perchloroethylene, ethyl acetate, amylacetate, butyl acetate, propylene glycol monomethyl ether and diethyleneglycol monomethyl ether, isopropyl alcohol, amyl alcohol, ethyleneglycol, propylene glycol, glycerine, and the like. Water is generallythe carrier of choice for the dilution of concentrates.

Suitable solid carriers include talc, pyrophyllite clay, silica,attapulgus clay, kieselguhr, chalk, diatomaceous earth, lime, calciumcarbonate, bentonite clay, Fuller's earth, cotton seed hulls, wheatflour, soybean flour, pumice, wood flour, walnut shell flour, lignin,and the like.

It is frequently desirable to incorporate one or more surface-activeagents into the compositions of the present invention. Suchsurface-active agents are advantageously employed in both solid andliquid compositions, especially those designed to be diluted withcarrier before application. The surface-active agents can be anionic,cationic or nonionic in character and can be employed as emulsifyingagents, wetting agents, suspending agents, or for other purposes.Typical surface active agents include salts of alkyl sulfates, such asdiethanolammonium lauryl sulfate: alkylarylsulfonate salts, such ascalcium dodecylbenzenesulfonate: alkylphenol-alkylene oxide additionproducts, such as nonylphenol-C18 ethoxylate: alcohol-alkylene oxideaddition products, such as tridecyl alcohol-C16 ethoxylate; soaps, suchas sodium stearate: alkylnaphthalenesulfonate salts, such as sodiumdibutylnaphthalenesulfonate; dialkyl esters of sulfosuccinate salts,such as sodium di(2-ethylhexyl) sulfosuccinate: sorbitol esters, such assorbitol oleate: quaternary amines, such as lauryl trimethylammoniumchloride; polyethylene glycol esters of fatty acids, such aspolyethylene glycol stearate: block copolymers of ethylene oxide andpropylene oxide; and salts of mono and dialkyl phosphate esters.

Other adjuvants commonly utilized in agricultural compositions includeantifoam agents, compatibilizing agents, sequestering agents, uvabsorbers, neutralizing agents and buffers, corrosion inhibitors, dyes,odorant, penetration aids, spreading agents, sticking agents, dispersingagents, thickening agents, freeze point depressants, antimicrobialagents, and the like. The addition of crop oil and crop oil concentratesis typical. The compositions can also contain other compatiblecomponents, for example, other herbicides, plant growth regulants,fungicides, insecticides, and the like and can be formulated with solid,particulate fertilizer carriers such as ammonium nitrate, urea and thelike or with liquid fertilizers.

The concentration of the active ingredients in the herbicidalcompositions of this invention is generally from about 0.001 to about 98percent by weight. Concentrations from about 0.01 to about 90 percent byweight are often employed. In compositions designed to be employed asconcentrates, the active ingredient is generally present in aconcentration from about 5 to about 98 weight percent, preferably about10 to about 90 weight percent. Such compositions are typically dilutedwith an inert carrier, such as water, before application. The dilutedcompositions usually applied to plants or their locus generally containabout 0.001 to about 5 weight percent active ingredient and preferablycontain about 0.01 to about 1.0 percent.

The present compositions can be applied by the use of conventionalground or aerial dusters and sprayers, by addition to irrigation water,and by other conventional means known to those skilled in the art.

General herbicide action is usually observed for compounds of Formula Iat rates of greater than about 300 g/Ha for either preemergence orpostemergence applications. Selective control of susceptible weeds incrops, such as cotton, soybeans, corn, rice, or wheat can beaccomplished with certain of the compounds at application rates of about2 g/Ha to about 500 g/Ha. An appropriate rate for each crop, compoundand circumstance can be determined by simple range finding tests usingthe teachings herein.

The term "herbicide" is used herein to mean an active ingredient whichcontrols or adversely modifies growth of plants. By "vegetationcontrolling" or "herbicidally effective" amount is meant an amount ofactive ingredient which causes an adversely modifying effect andincludes deviations from natural development, killing, regulation,dessication, retardation, and the like. The terms "plants" and "weeds"are meant to include germinant seeds, emerging seedlings and establishedvegetation. "Undesirable vegetation" is plant life present in a placewhere it is not wanted.

Herbicidal activity is exhibited by the compounds of the presentinvention when they are applied directly to the plant or to the locus ofthe plant at any stage of growth or before emergence. The effectobserved depends upon the plant species to be controlled, the stage ofgrowth of the plant, the application parameters of dilution and spraydrop size, the particle size of solid components, the environmentalconditions at the time of use, the specific compound employed, thespecific adjuvants and carriers employed, and the like, as well as theamount of chemical applied. These and other factors can be adjusted asis known in the art to promote selective herbicidal action.

EXAMPLES EXAMPLE 1 Preparation of 1,1-bis(2-methoxyphenyl)cyclopropane.

Sodium hydride (4.4 g of 60 percent oil dispersion) was placed in aflask with 140 ml of dimethoxyethane. This mixture was cooled with anice bath and 22.3 g of triethyl phosphonoacetate was added dropwise withstirring over a 30 min period. A murky yellow solution was obtained.2,2'-Dimethoxybenzophenone (20.2 g) was added and the resulting mixturewas heated at reflux with stirring for 20 hours. It was then allowed tocool to ambient temperature and was diluted with 500 ml of ether. Theresulting mixture was washed with 3-200 ml portions of 1 N hydrochloricacid and with saturated sodium bicarbonate, dried over magnesiumsulfate, filtered, and concentrated by evaporation under reducedpressure to obtain a turbid, viscous yellow oil. This material was foundby gas chromatography to be about 79 percent one compound. It wasdissolved in 100 ml of tetrahydrofuran and the solution added dropwisewith stirring to a slurry of 4.70 g of lithium aluminum hydride in 100ml of tetrahydrofuran over a 40 min period. An exothermic reactionensued. The mixture was heated at reflux for 3 hours and allowed tostand at ambient temperature overnight. About 100 ml of 10 percentsulfuric acid was added carefully with stirring to quench the excesslithium aluminum hydride. About 700 ml of ether was then added and thelayers were separated. The ether layer was extracted with water, 10percent hydrochloric acid, 10 percent potassium hydroxide, and brine. Itwas then dried over magnesium sulfate, filtered, and concentrated byevaporation under reduced pressure. The residue was purified byfiltration chromatography on silica eluting with a 10:90 mixture ofether and hexane. The solvents were removed by evaporation under reducedpressure to obtain 5.6 g (26 percent of theory) of the title compound aspale yellow crystals melting at 146-149° C. The carbon-13 and proton nmrspectra were in agreement with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₈ O₂ : %C, 80.3: %H, 7.13;

Found: %C, 79.9: %H, 7.02;

EXAMPLE 2 Preparation of 1,1-Bis(2-hydroxyphenyl)cyclopropane.

1,1-Bis(2-methoxyphenyl)cyclopropane (10.0 g, 0.039 mole) was combinedwith 60 ml of dichloromethane and the mixture was cooled in an ice bathand then treated with 10.0 ml of bromodimethylborane with cooling andstirring. The starting material was consumed in less than 1 hour asdetermined by gas-liquid chromatography. The mixture was then dilutedwith 500 ml of ether and the resulting solution was extracted twice withwater and then with water saturated with ammonium chloride, dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain 9.0 g (101 percent of theory) of the titlecompound as a brownish-black solid: m.p., 158-160° C. This eluted as oneclean peak in gas-liquid chromatography and had a proton NMR spectrumconsistent with the assigned structure.

Elemental analysis:

Calc. for C₁₅ H₁₄ O₂ : %C, 79.6: %H, 6.21;

Found: %C, 79.0: %H, 6.21;

2,2-Bis(2-hydroxyphenyl)butane was prepared in the same manner from2,2-bis(2-methoxyphenyl)butane. The proton NMR and infrared spectra wereconsistent with the assigned structure.

EXAMPLE 3 Preparation of Spiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylic Acid.

An 18.5 g (0.082 mole) sample of unpurified1,1-bis(2-hydroxyphenyl)cyclopropane was combined with 44.0 g (0.32mole) of potassium carbonate, 2.0 g (0.012 mole) of potassium iodide,8.0 ml of dichloroacetic acid, and 400 ml of isopropyl alcohol. Themixture was heated at reflux with stirring for 24 hours. Another 8.0 mlof dichloroacetic acid was added and the mixture heated at reflux withstirring for another 48 hours. The volatiles were then removed byevaporation under reduced pressure. The solid that remained wasdissolved in 300 ml of water. The resulting solution was extracted with500 ml of ether, acidified with concentrated hydrochloric acid(carefully due to foaming), and then extracted with three 500 mlportions of ether. The latter ether extracts were dried over magnesiumsulfate, filtered, and concentrated under reduced pressure to obtain thetitle compound in crude form as a solid.

A purified sample of the title compound was obtained by hydrolysis ofits methyl ester from Example 4. A 0.070 g sample was dissolved in 10 mlof methanol containing 3 ml of 10 percent aqueous potassium hydroxideand the solution allowed to stir overnight. The mixture was then dilutedwith 10 ml of water and the resulting solution extracted with 50 ml ofether. The aqueous solution was acidified with 10 percent hydrochloricacid and then extracted with ether. The ether extract was dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain a solid. This was recrystallized from a 1:1mixture of chloroform and hexane to obtain 0.33 g of the title compoundas a white powder melting at 142.5-145° C. The proton NMR and infraredspectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₄ O₄ : %C, 72.3; %H, 5.00;

Found: %C, 72.3: %H, 4.79;

EXAMPLE 4 Preparation of Methyl Spiro(cyclopropane-1,12'(12'H,)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.

The crudespiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylicacid from Example 3 was dissolved in 500 ml of methanol and 2.0 ml ofsulfuric acid added. The mixture was heated at reflux and stirred for 3hours. About half of the methanol was removed by evaporation underreduced pressure and the remaining solution was diluted with 1.5 1 ofether. The solution obtained was extracted several times with water andthen with brine and was then dried over magnesium sulfate, filtered, andconcentrated by evaporation under reduced pressure to obtain the titlecompound in impure form. This was purified by filtration chromatography,eluting with a 9 1 mixture of hexane and ether to obtain the product asa pale yellow crystalline solid. This was recrystallized from methanolto obtain 9.55 g of the title compound as pale tan crystals melting at123-126° C. The proton and carbon NMR and infrared spectra wereconsistent with the assigned structure.

Elemental analysis:

Calc. for C₁₈ H₁₆ O₄ : %C, 73.0: %H, 5.40;

Found: %C, 72.9: %H, 5.41;

EXAMPLE 5 Preparation of 2-Propyl Spiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.

Methylspiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate(0.60 g) was dissolved in 30 ml of 2-propanol and a trace of sodiummethoxide was added. The mixture was allowed to stir until esterinterchange was complete as determined by gas-liquid chromatography. Thesolution was diluted with 150 ml of ether and the resulting solution wasextracted several times with water, dried over magnesium sulfate andconcentrated by evaporation under reduced pressure to obtain 0.38 g ofthe title compound as a white crystalline product melting at 84-87° C.The proton and carbon NMR and infrared spectra were consistent with theassigned structure.

Elemental analysis:

Calc. for C₂₀ H₂₀ O₄ : %C, 74.1: %H, 6.21;

Found: %C, 74.5; %H, 6.24;

The ethyl ester was obtained in the same manner substituting ethanol for2-propanol and was found to be pale yellow crystals melting at 114-115°C. The proton and carbon NMR and infrared spectra were consistent withthe assigned structure.

Elemental analysis:

Calc. for C₁₉ H₁₈ O₄ : %C, 73.5: %H, 5.84;

Found: %C, 74.2: %H, 5.80;

EXAMPLE 6 Preparation ofSpiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxamicAcid.

Methylspiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate(1.30 g), hydroxylamine hydrochloride (1.03 g), sodium methoxide (0.74g) and 25 ml of methanol were combined and heated to reflux withstirring. After a brief period, the heat was removed and the mixtureallowed to stir at ambient temperature overnight. Ether (150 ml) wasadded and the resulting solution was extracted with dilute hydrochloricacid, water (several times) and finally with saturated aqueous ammoniumchloride. The ethereal solution was then dried over magnesium sulfate,filtered, and concentrated by evaporation under reduced pressure toobtain the title compound as a fluffy white solid. This wasrecrystallized from ethyl acetate/hexane to obtain a 0.52 g first cropand a 0.20 g second crop of the title compound as a fine white powdermelting at 127-135° C. with decomposition. The proton NMR and infraredspectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₅ NO₄ : %C, 68.7: %H, 5.09; %N, 4.71;

Found: %C, 67.8: %H, 5.29: %N, 4.32;

EXAMPLE 7 Preparation of 1,1-Bis(2-methoxyphenyl)ethanol.

2,2'-Dimethoxybenzophenone (24.2 g, 0.14 mole) and 400 ml of ether wereplaced in a 1 1 flask and stirred at ambient temperature and methylmagnesium bromide (40 ml of 3.0 M solution in ether) was added dropwise.The resulting mixture was stirred overnight and then a few ml of waterwere added to quench the Grignard reagent. About 300 ml of ethyl acetateand 250 ml of 10 percent hydrochloric acid were then added and themixture was shaken. The organic layer was next recovered, extracted with100 ml of water and 100 ml of saturated sodium bicarbonate, dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain 25.6 g (98 percent of theory) of the titlecompound as a white solid melting at 122-123° C. The proton NMR spectrumwas consistent with the assigned structure.

EXAMPLE 8 Preparation of 1,1-Bis(2-methoxyphenyl)ethene.

1,1-Bis(2-methoxyphenyl)ethanol (25.6 g) was combined with 250 ml ofacetic anhydride and the mixture was heated at reflux for 4 hours. Adrop of concentrated sulfuric acid was added and the heating continuedfor 10 min. The opaque brown mixture obtained was allowed to cool andwas diluted with ether. The resulting solution was extracted twice withwater, dried over magnesium sulfate, filtered, and concentrated byevaporation under reduced pressure to obtain a brownish-black solid.This was recrystallized from methanol to obtain 14.0 g of the titlecompound as tan crystals melting at 88-90° C. The proton NMR spectrumwas consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₅ O₄ : %C, 80.0; %H, 6.71;

Found: %C, 79.9: %H, 6.68;

EXAMPLE 9 Preparation of 2,2-Bis(2-methoxyphenyl)propane.

1,1-Bis(2-methoxyphenyl)ethene (15.6 g), toluene (35 ml) and anisole (35ml) were combined in a flask and 35 ml of a 3.7M hexane solution ofRed-Al was added. The mixture was heated to reflux with stirringwhereupon it turned dark red. After 2 hours the heat was removed and themixture was allowed to stir overnight. The excess hydride reagent wascarefully quenched with 1.0N hydrochloric acid. The mixture was thendiluted with ether and the ethereal solution separated, dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain a golden-brown oil. This was triturated withhexane to obtain 3.70 of the title compound. The proton and carbon NMRspectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₅ O₄ : %C, 79.7; %H, 7.81;

Found: %C, 79.6; %H, 7.86;

A second crop amounting to 2.45 g was obtained by adding methanol.

EXAMPLE 10 Preparation of 2,2-Bis(2-hydroxyphenyl)propane.

Sodium hydride (2.60 g of 60 percent dispersion in oil) was placed in a1 1 flask and extracted twice with pentane. To this was added first 250ml of dimethylformamide and then, dropwise with stirring over 1 hour,6.0 ml of ethanethiol in 40 ml of dimethylformamide.2,2-Bis(2-methoxyphenyl)propane (8.0 g, 31 mmol) in 100 ml ofdimethylformamide was then added and the mixture was heated at refluxwith stirring for 24 hours and allowed to stand at ambient temperaturefor another approximately 18 hours. One 1 of ether was added and theresulting solution was extracted with water and twice with 4.0N sodiumhydroxide solution. The combined aqueous extracts were neutralized withconcentrated hydrochloric acid to a pH of about 9-10. Ether (500 ml) wasthen added and, after shaking, the ether layer was separated, dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain about 3 g of the title compound as a brownoil containing some dimethylformamide. The proton NMR spectrum wasconsistent with the assigned structure.

EXAMPLE 11 Preparation of12,12-Dimethyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylic Acid andMethyl 12,12-Dimethyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylate.

2,2-Bis(2-hydroxyphenyl)propane (3 g of unpurified), potassium carbonate(6.5 g), potassium iodide (0.67 g) and dichloroacetic acid (1.0 ml atfirst, then another 1.2 ml) were combined in isopropyl alcohol andtreated as in Example 3 to obtain the title acid in impure form. Thiswas esterified by the procedure of Example 4 to obtain the methyl ester.The methyl ester obtained was purified by column chromatography onsilica gel, eluting with an 85:15 mixture of hexane and ether, and thenby recrystallization from ether-pentane to obtain 0.45 g of the titlemethyl ester compound as white crystals melting at 91-92° C. The protonNMR and infrared spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₈ H_(18O) ₄ : %C, 72.5: %H, 6.08;

Found: %C, 72.4; %H, 5.87;

A sample of the methyl ester was hydrolyzed as in Example 3 to obtainthe title acid compound as a pale yellow-orange glass melting below 50°C.

EXAMPLE 12 Preparation of 2,2-Bis(2-methoxyphenyl)butane.

1,1-Bis(2-methoxyphenyl)ethene (5.6 g) was dissolved in 25 ml oftetrahydrofuran and 25 ml of a 1.3M solution of methyl lithium in etherwas added dropwise with stirring. The solution became dark red andexothermed. After 2 hours, 5.0 ml of methyl iodide was added slowly withstirring. The solution again exothermed. When all of the methyl iodidehad been added the starting material was found to be completely consumedand replaced by a single product by gas-liquid chromatography. About 300ml of ether was added and the resulting solution was extracted with 100ml of water and then 100 ml of brine, dried over magnesium sulfate,filtered, and concentrated by evaporation under reduced pressure toobtain 5.46 g (88 percent of theory) of the title compound as a paleyellow crystalline solid melting at 49-52° C. The proton and carbon NMRand infrared spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₈ H₂₂ O₂ : %C, 80.0; %H, 8.20;

Found: %C, 80.3; %H, 8.09;

EXAMPLE 13 Preparation of12-Ethyl-12-methyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylic Acid andMethyl 12-Ethyl-12-methyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylate.

2,2-Bis(2-hydroxyphenyl)butane in impure form was condensed withdichloroacetic acid as in Example 3 to obtain the title acid in impureform. This was esterified with methanol by the procedure of Example 4 toobtain a mixture of 2 isomers of the title ester in an approximately1:1.5 ratio as determined by gas-liquid chromatography. This was columnchromatographed eluting with a 90:10 mixture of hexane and ether toobtain a small fraction that was about 95 percent one isomer and alarger fraction that was a 1:1 mixture of cis/trans isomers. Bothfractions were oils. The two fractions obtained were separatelyhydrolyzed to the title acid using the procedure of Example 3. Thesingle isomer fraction gave a single isomer of the title acid as an oilwhich crystallized from ether-hexane on standing in an open dessicatorand melted at 123-124° C. The mixed isomer fraction gave a 1:1 mixtureof the isomers of the title acid as a glassy solid melting at about80-85° C. The proton NMR and infrared spectra of both products wereconsistent with the assigned structures, including the isomerdistribution.

Elemental analysis:

Calc. for C₁₈ H₁₈ O₄ : %C, 72.5: %H, 6.08;

Found(single isomer): %C, 72.4; %H, 6.15;

Found(1:1 isomer mix): %C, 72.2: %H, 5.87;

EXAMPLE 14 Preparation of 1,1-Bis(2-hydroxyphenyl)ethanol.

A solution of 10.71 g of 2,2'-dihydroxybenzophenone in 100 ml of etherwas prepared and added slowly with stirring to 76 ml of an ice-bathcooled 3.0M solution of methyl magnesium bromide in ether. The ice bathwas removed and the mixture was allowed to react for another hour atambient temperature and then it was heated at reflux for 2 hours. Thereaction was quenched with 100 ml of saturated aqueous ammoniumchloride, diluted with 100 ml of ether, and the phases separated. Theaqueous phase was extracted with 2-100 ml portions of ether. The organicphase and ether extracts were combined and extracted with saturatedaqueous ammonium chloride, dried over magnesium sulfate, filtered, andconcentrated by evaporation under reduced pressure to obtain a yellowsolid. This was recrystallized from an ether-hexane mixture to obtain10.06 g (94 percent of theory) of the title compound as light yellowcrystals. The proton NMR spectrum was consistent with the assignedstructure.

Elemental analysis:

Calc. for C₁₄ H₁₄ O₃ : %C, 73.0: %H, 6.13, ;

Found: %C, 73.0: %H, 6.23;

1,1-Bis(2-hydroxyphenyl)propanol was prepared similarly using ethylmagnesium bromide.

EXAMPLE 15 Preparation of 1,1-Bis(2-hydroxyphenyl)ethane.

1,1-Bis(2-hydroxyphenyl)ethanol (8.57 g) dissolved in 40 ml ofdichloromethane was cooled with an ice bath and to this was addedsequentially with stirring 3.70 ml of trifluoroacetic acid in 20 ml ofdichloromethane and (dropwise) 7.67 ml of triethylsilane in 20 ml ofdichloromethane. The mixture was allowed to warm to room temperature andreact for another 2 hours. Ether and water were added and the phasesseparated. The organic phase was extracted with several small portionsof 2N sodium hydroxide and the extracts were combined and acidified withhydrochloric acid. The resulting mixture was extracted with ether andthe ether extract was dried over magnesium sulfate, filtered, andconcentrated by evaporation under reduced pressure to obtain 6.10 g ofthe title compound as a brown oil.

1,1-Bis(2-hydroxyphenyl)propane was prepared similarly from1,1-bis(2-hydroxyphenyl)propanol and1-(3-chloro-2-methoxy-methoxyphenyl)-1-(2-methoxyphenyl)ethane wasprepared similarly from1-(3-chloro-2-methoxymethoxyphenyl)-1-(2-methoxyphenyl)ethanol.

EXAMPLE 16 Preparation of Methyl12-Methyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylate.

1,1-Bis(2-hydroxyphenyl)ethane was treated with dichloroacetic acid,potassium carbonate, and potassium iodide in isopropyl alcohol as inExample 3 and the product obtained was esterified with methanol as inExample 4 to obtain 1.71 g of the title compound as a mixture of cis andtrans isomers. A portion of this was recrystallized from ether to obtaina pure sample of the cis isomer of the title compound as a white solidmelting at 146-147° C. The geometry was determined by proton NMRspectroscopy.

Elemental analysis:

Calc. for C₁₇ H₁₆ O₄ : %C, 71.8: %H, 5.67;

Found: %C, 71.5; %H, 5.77;

Methyl 12-ethyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylate was preparedsimilarly from 1,1-bis(2-hydroxyphenyl)propane. A 1:1 mixture of cis andtrans isomers was obtained as a white solid melting at 134.5-135.5° C.after recrystallization with methylcyclohexane. The assigned structurewas consistent with the proton NMR spectrum.

Elemental analysis:

Calc. for C₁₈ H₁₈ O₄ : %C, 72.5: %H, 6.08,;

Found: %C, 72.6; %H, 5.95;

EXAMPLE 17 Preparation of12-Ethyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylic Acid.

Methyl 12-ethyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylate as a 1:1mixture of isomers (1.25 g) was hydrolyzed as in Example 3 to obtain thetitle compound (as a 1:1 mixture of cis and trans isomers) as anoff-white solid melting at 142-145° C. The assigned structure wasconsistent with the proton NMR spectrum.

Elemental analysis:

Calc. for C₁₇ H₁₆ O₄ : %C, 71.8: %H, 5.67;

Found: %C, 71.1; %H, 5.50;

EXAMPLE 18 Preparation of1-(3-Chloro-2-methoxy-methoxyphenyl)-1-(2-methoxyphenyl)ethanol.

1-Chloro-2-methoxymethoxybenzene (20.0 g) was combined with 72.5 ml of1.6M n-butyl lithium in hexane at 0° C. with stirring and allowed toreact for 4 hours. A solution of 16.0 ml of 2-methoxyacetophenone in 20ml of tetrahydrofuran was then added with stirring. After a shortreaction period, water and ether were added and the ether layer wasdried over magnesium sulfate, filtered, and concentrated by evaporationunder reduced pressure to obtain an oil. This was purified by liquidchromatography, eluting with a 95:5 mixture of hexane and ethyl acetate,to obtain 6.67 g of the title compound as an oil. The assigned structurewas consistent with the proton NMR spectrum.

EXAMPLE 19 Preparation of Methyl2-Chloro-12-methyl-12H-dibenzo[d,g][1,3]dioxocin-6-carboxylate.

1-(3-Chloro-2-hydroxyphenyl)-1-(2-hydroxyphenyl)ethane was condensedwith dichloroacetic acid as in Example 3 to obtain the acid of the titlecompound in impure form. This was esterified with methanol by theprocedure of Example 4 to obtain a mixture of cis and trans isomers ofthe title compound. The mixture was liquid chromatographed to obtain onefraction identified as the trans isomer melting at 144-145° C. and asecond fraction containing an approximately 3.7:1 ratio of the isomersmelting at 124-136° C. The assigned structures were consistent with theproton NMR spectra.

Elemental analysis:

Calc. for C₁₇ H₁₅ O₄ Cl: %C, 64.1; %H, 4.74;

Found (trans isomer): %C, 64.1: %H, 4.83;

Found (mixed isomers): %C, 64.3: %H, 4.91;

EXAMPLE 20 Preparation of(2-Methoxyphenyl)(3-methyl-2-methoxymethoxyphenyl)methanol.

1-Methyl-2-methoxymethoxybenzene (15.2 g) was added to a mixture of 75ml of a 1.6M solution of n-butyl lithium in hexane and 18.1 ml oftetramethylethylenediamine at 0° C. with stirring. After 4 hours, 13.6 gof o-anisaldehyde dissolved in 30 ml of tetrahydrofuran was added. Themixture was allowed to react for 0.5 hour and was then poured into amixture of ice and saturated aqueous ammonium chloride. The resultingmixture was extracted with ether and the ether extract was dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain 39.5 g of the title compound as an off-whitesolid. The assigned structure was consistent with the proton NMRspectrum.

EXAMPLE 21 Preparation of2-Methoxymethoxy-3-methyl-2'-methoxybenzophenone.

A solution of 8.72 ml of oxalyl chloride in 300 ml of dichloromethanewas cooled with a dry ice-acetone bath and a solution of 13.9 ml ofdimethyl sulfoxide in 50 ml of dichloromethane was added dropwise withstirring. After 30 min,(2-methoxyphenyl)(3-methyl-2-methoxymethoxyphenyl)methanol (26.4 g)dissolved in 100 ml of dichloromethane was added slowly with stirringand the mixture allowed to react for 1 hour. Triethylamine (64 ml) wasthen added and the resulting mixture was stirred another 30 min cold andthen allowed to warm to room temperature. The product mixture wasextracted sequentially with water, 5 percent hydrochloric acid, water,and 5 percent sodium carbonate. It was then dried over magnesiumsulfate, filtered, and concentrated by evaporation under reducedpressure to obtain an oil. This was purified by preparative liquidchromatography to obtain the title compound as an oil. The assignedstructure was consistent with the proton NMR spectrum.

EXAMPLE 22 Preparation of1-(2-Methoxymethoxy-3-methyl)-1-(2-methoxyphenyl)cyclopropane.

2-Methoxymethoxy-3-methyl-2'-methoxybenzophenone (17.5 g) was combinedwith the sodium salt of triethyl phosphonoacetate (2.2 equivalents) in250 ml of dimethoxyethane and the mixture heated at reflux with stirringfor 2 days. Water and ether were added and the organic phase wasseparated, extracted with water, dried over magnesium sulfate, filtered,and concentrated by evaporation under reduced pressure to obtain an oil.This was purified by preparative liquid chromatography, eluting with a90:10 mixture of hexane and acetone, to obtain ethyl3-(2-methoxy-phenyl)-3-(2-methoxymethoxy-3-methylphenyl)propenoate as anintermediate consisting of a mixture of isomers. The assigned structurewas consistent with the proton NMR spectrum. This was dissolved in 50 mlof tetrahydrofuran and treated with 61 ml of a solution of 1M lithiumaluminum hydride in tetrahydrofuran at ambient temperature withstirring. The mixture was heated at reflux with stirring for 4 hours. Itwas then allowed to cool, was quenched with 10 percent sulfuric acid,and was diluted with ether. The organic phase was separated, extractedwith water, dried over magnesium sulfate, filtered, and concentrated byevaporation under reduced pressure to obtain a crude product. This waspurified by preparative liquid chromatography, eluting with a 95:5mixture of hexane and acetone, to obtain 6.01 g of the title compound asa gum. The assigned structure was consistent with the proton NMRspectrum.

EXAMPLE 23 Preparation of Methyl4'-Methylspiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.

1-(3-Methyl-2-hydroxyphenyl)-1-(2-hydroxyphenyl)cyclopropane wascondensed with dichloroacetic acid as in Example 3 to obtain the acid ofthe title compound in impure form. This was esterified with methanol bythe procedure of Example 4 to obtain the title compound in impure form.This was purified by liquid chromatography, eluting with a 90:10 mixtureof hexane and acetone to obtain 1.29 g of the title compound as a whitecrystalline solid melting at 98-99° C. The assigned structure wasconsistent with the proton and carbon NMR and infrared spectra.

Elemental analysis:

Calc. for C₁₉ H₁₈ O₄ : %C, 73.5: %H, 5.85;

Found: %C, 71.2; %H, 5.84;

EXAMPLE 24 Preparation of(3-Chloro-2-methoxy-methoxyphenyl)(2-methoxymethoxyphenyl)methanol.

A 1.6M solution of n-butyl lithium in hexane (140 ml) was placed in a 1l flask and cooled in an ice bath. To this was added with stirring 34 mlof tetramethylethylenediamine and, after a 10 min reaction period, 34.5g of 1-chloro-2-methoxymethoxybenzene (dropwise over a 30 min period). Apale orange suspension formed and this was stirred for 4 hourscontinuing the ice bath cooling. A solution of 34.5 g of2-methoxymethoxybenzaldehyde in 30 ml of tetrahydrofuran was added withstirring and cooling. The reaction was exothermic. When the addition wascomplete, the mixture was allowed to warm to room temperature and wasthen quenched carefully with water. The resulting mixture was pouredinto a mixture of 1 l of ethyl acetate and 500 ml of aqueous ammoniumchloride. The phases were separated and the organic phase was extractedtwice with water and once with brine, dried over magnesium sulfate,filtered, and concentrated by evaporation under reduced pressure toobtain a viscous, pale orange oil. This was purified by filtrationchromatography, eluting with mixtures of hexane and dichloromethanestarting with pure hexane and ending with pure dichloromethane, toobtain 52.2 g (77 percent of theory) of the title compound as a paleyellow oil. The proton and carbon NMR and infrared spectra wereconsistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₉ C10₅ : %C, 60.3: %H, 5.65;

Found: %C, 60.6; %H, 5.57;

(3-Methoxy-2-methoxymethoxyphenyl)(2-methoxymethoxyphenyl)methanol (33.7g) was prepared similarly from 33.6 g of 2-methoxyphenol and 33.2 g of2-methoxymethoxybenzaldehyde and characterized by proton NMRspectroscopy.

EXAMPLE 25 Preparation of3-Chloro-2-methoxymethoxy-2'-methoxymethoxybenzophenone.

A solution of 16.0 ml of oxalyl chloride in 500 ml of dichloromethanewas placed in a 1 l flask and cooled with a dry ice-acetone bath.Dimethyl sulfoxide (14.0 ml) was added dropwise with stirring over a 10min period. After a 40 min reaction period, a solution of 51.0 g of(3-chloro-2-methoxymethoxyphenyl)(2-methoxymethoxyphenyl)methanol in 120ml of dichloromethane was added dropwise over a 45 min period withstirring at about -78° C. and allowed to react another 45 min. An orangesuspension formed. Triethylamine (50 ml) was added and the slurry wasswirled occasionally and was allowed to warm to room temperature. Theslurry was diluted with 1 l of ether and the resulting mixture wasextracted with 3-300 ml portions of water, 300 ml of 2 percenthydrochloric acid, and 200 ml of saturated aqueous sodium bicarbonate,dried over magnesium sulfate, filtered, and concentrated by evaporationunder reduced pressure to obtain 50.5 g of the title compound as aviscous pale orange-tinted oil. The proton and carbon NMR spectra wereconsistent with the assigned structure.

3-Methoxy-2-methoxymethoxy-2'-methoxymethoxybenzophenone was preparedsimilarly from(3-methoxy-2-methoxymethoxyphenyl)(2-methoxymethoxyphenyl)methanol andcharacterized by proton NMR spectroscopy.

EXAMPLE 26 Preparation of1-(3-Chloro-2-methoxymethoxyphenyl)-1-(2-methoxymethoxyphenyl)ethene.

A 1.0M solution of trimethylsilylmethyl lithium in pentane (160 ml) wasadded with stirring to a solution of 50.5 g of3-chloro-2-methoxymethoxy-2'-methoxymethoxybenzophenone in 500 ml oftetrahydrofuran over a 45 min period. There was a mild exotherm.Analysis by gas-liquid chromatography indicated the reaction wasincomplete so another 10 ml of the trimethylsilylmethyl lithium solutionwas added. After a 20 min reaction period 7.3 g of potassium t-butoxidewere added and the reaction was heated to reflux with a heating mantleand held there for 40 min. The mixture was then allowed to cool and wasdiluted with 1 l of ether. The ethereal solution was extracted with6-300 ml portions of water and 200 ml of brine, dried over magnesiumsulfate, filtered, and concentrated by evaporation under reducedpressure to obtain 50.2 g of the title compound as a pale orange oil.The proton NMR spectrum was consistent with the assigned structure.

1-(3-Methoxy-2-methoxymethoxyphenyl)-1-(2-methoxymethoxyphenyl)ethenewas prepared similarly from3-methoxy-2-methoxymethoxy-2'-methoxymethoxybenzophenone andcharacterized by proton NMR spectroscopy.

EXAMPLE 27 Preparation of1-(3-Chloro-2-methoxy-methoxyphenyl)-1-(2-methoxymethoxyphenyl)cyclopropane.

Phenylthiomethyl lithium was prepared by adding 120 ml of 2.5M butyllithium in hexane to a solution of 37.3 g of thioanisole and 33.7 g of1,4-diazabicyclo[2,2,2]octane in 400 ml of tetrahydrofuran dropwise withstirring at 0° C. and then allowing the mixture to react for 45 min at0° C. and 1 hour at room temperature. A solution of 50.2 g of1-(3-chloro-2-methoxymethoxyphenyl)-1-(2-methoxymethoxyphenyl)ethenedissolved in 100 ml of tetrahydrofuran was added slowly to this atambient temperature with stirring. A brick red color developed. Themixture was heated to reflux for about 30 min. Analysis by gas-liquidchromatography indicated that the reaction was complete. The mixture wascooled, diluted with ether, and quenched with water. The solution wasextracted several times with water and once with brine, dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain about 80 ml of a pale orange oil. This wassubjected to a bulb-to-bulb distillation at up to 120° C. and 0.3 mm ofmercury pressure. The thioanisole impurity was removed and a product cutof less than 5 ml was collected. Considerable decomposition took place.The product cut was partially purified by liquid chromatography, elutingwith a 95:5 mixture of hexane and ether to obtain 1.8 g of the titlecompound of about 82 percent purity (gas-liquid chromatography) as aviscous oil. The proton NMR spectrum was consistent with the assignedstructure.

1-(3-Methoxy-2-methoxymethoxyphenyl)-1-(2-methoxymethoxyphenyl)cyclopropanewas prepared similarly from1-(3-methoxy-2-methoxymethoxyphenyl)-1-(2-methoxymethoxyphenyl)etheneand characterized by proton NMR spectroscopy.

EXAMPLE 28 Preparation of1-(3-Chloro-2-hydroxy-phenyl)-1-(2-hydroxyphenyl)cyclopropane.

A catalytic amount (0.05 g) of p-toluenesulfonic acid was added to asolution of 1.8 g of impure1-(3-chloro-2-methoxymethoxyphenyl)-1-(2-methoxymethoxyphenyl)cyclopropanein 45 ml of methanol and the mixture heated at reflux with stirring for1 hour. It was then concentrated by evaporation under reduced pressureand diluted with 120 ml of ethyl acetate. The resulting solution wasextracted with saturated aqueous sodium bicarbonate, dried overmagnesium sulfate, filtered, and concentrated by evaporation underreduced pressure to obtain 1.45 g of a viscous oil. This was found byproton NMR analysis to retain some methoxymethoxy groups so theprocedure was repeated, this time refluxing for 2.5 hours. The titlecompound was obtained as a beige solid amounting to 1.41 g. The protonand carbon NMR spectra were consistent with the assigned structure.

1-(3-Methoxy-2-hydroxyphenyl)-1-(2-hydroxyphenyl)cyclopropane wasprepared similarly from1-(3-methoxy-2-methoxymethoxyphenyl)-1-(2-methoxymethoxyphenyl)cyclopropaneand characterized by proton NMR spectroscopy.

EXAMPLE 29 Preparation of Methyl4'-Chlorospiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.

1-(3-Chloro-2-hydroxyphenyl)-1-(2-hydroxyphenyl)cyclopropane wascondensed with dichloroacetic acid as in Example 3 to obtain the acid ofthe title compound in impure form. This was esterified with methanol bythe procedure of Example 4 to obtain the title compound in impure form.This was twice purified by liquid chromatography, eluting with a 90:10mixture of hexane and ether, and crystallizing from hexane to obtain asa first crop 0.30 g of the title compound as a white crystalline solidmelting at 105-111° C. A second crop of about 94 percent purity was alsoobtained. The proton and carbon NMR spectra were consistent with theassigned structure.

Elemental analysis:

Calc. for C₁₈ H₁₅ C10₄ : %C, 65.4; %H, 4.57;

Found: %C, 64.7: %H, 4.61;

EXAMPLE 30 Preparation of4'-Chlorospiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylicAcid.

Methyl4'-chlorospiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylatewas hydrolyzed using the procedure of Example 4. The crude product waspurified by recrystallization from an ether/hexane mixture to obtain thetitle compound as white granules melting at 154-158° C. The proton andcarbon NMR spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₃ C10₄ : %C, 64.5; %H, 4.14;

Found: %C, 64.4: %H, 4.06;

EXAMPLE 31 Preparation of Methyl4'-Methoxyspiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.

1-(3-Methoxy-2-hydroxyphenyl)-1-(2-hydroxyphenyl)cyclopropane wascondensed with dichloroacetic acid as in Example 3 to obtain the acid ofthe title compound in impure form. This was esterified with methanol andpurified by the procedure of Example 4 to obtain the title compound as awhite crystalline solid melting at 140-141° C. The proton NMR andinfrared spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₉ H₁₈ O₅ : %C, 69.9: %H, 5.56;

Found: %C, 69.8: %H, 5.54;

EXAMPLE 32 Preparation of(2-Methoxymethoxyphenyl)(3,4-dimethoxy-2-methoxymethoxyphenyl)methanol.

A 1.6M solution of butyl lithium in hexane (91 ml, 146 mmol) was placedin an oven-dried 500 ml 3-necked flask and cooled to 0° C. and then 22.5ml (20.1 mmol) of tetramethylethylenediamine was added with stirring.After a 10 min reaction period, a solution of 18.3 g (133 mmol) ofmethoxymethoxybenzine was added and the mixture allowed to stir forabout 3.5 hours at 0° C. 3,4-Dimethoxy-2-methoxymethoxybenzaldehyde(30.0 g, 133 mmol) in 18 ml of tetrahydrofuran was then added dropwisewith stirring. The mixture was allowed to warm to room temperature andstir for 1 hour and was then quenched with 50 ml of saturated aqueousammonium chloride. The resulting mixture was extracted with 200 ml ofethyl acetate three times. The combined extracts were dried overmagnesium sulfate and concentrated by evaporation under reduced pressureto obtain 48.5 g of an oil. This was purified by silica gelchromatography on an 8 in diameter sintered glass funnel eluting withmixtures of hexane and dichloromethane increasing from 38 percent to 75percent dichloromethane to obtain 32.2 g (68 percent of theory) of thetitle compound as a yellow oil. The proton and carbon NMR and infraredspectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₉ H₂₄ O₇ : %C, 62.6; %H, 6.41;

Found: %C, 62.7: %H, 6.64;

EXAMPLE 33 Preparation of2'-Methoxymethoxy-3,4-dimethoxy-2-methoxymethoxybenzophenone.

A mixture 12.3 g (126 mmol) of chromium trioxide in 153 ml ofdichloromethane was cooled to 0° C. and 20.3 ml (252 mmol) of pyridinewere added with stirring to obtain, after 45 min, a yellow-brownsolution (Collin's reagent).(2-Methoxymethoxyphenyl)(3,4-dimethoxy-2-methoxymethoxyphenyl)methanol(7.67 g, 21 mmol) was added with stirring and the mixture allowed towarm to room temperature with stirring overnight. Twenty grams offlorisil were added and the mixture was concentrated by evaporationunder reduced pressure and filtered through celite and then furthereluted with ether. The resulting mixture was concentrated under reducedpressure and purified by liquid chromatography using a Waters Prep 500Chromatograph with a silica gel column and eluting with a 70:30 mixtureof hexane and ethyl acetate to obtain 6.0 g (79 percent of theory) ofthe title compound as an oil. The proton and carbon NMR and infraredspectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₉ H₂₂ O₇ : %C, 63.0; %H, 6.12;

Found: %C, 62.9: %H, 5.90;

EXAMPLE 34 Preparation of1-(2-Methoxymethoxy-phenyl)-1-(3,4-dimethoxy-2-methoxymethoxyphenyl)ethene

A solution of 1.84 g (5.1 mmol) of2'-methoxymethoxy-3,4-dimethoxy-2-methoxymethylbenzophenone in 17 ml ofdry tetrahydrofuran was cooled to 0° C. and 9.1 ml of 1.0M (9.1 mmol) oftrimethylsilylmethyl lithium in pentane was added with stirring. After2.5 hours, 0.38 ml (4.1 mmol) of t-butyl alcohol and 231 mg (2.0 mmol)of potassium t-butoxide were added and the mixture was heated at refluxwith stirring for 4 hours. The resulting mixture was diluted with 40 mlof ether and the solution obtained was dried over magnesium sulfate andconcentrated by evaporation under reduced pressure to obtain 2.0 g of anoil. This was purified by filtration chromatography on a 2 in. bed ofsilica gel eluting with hexane containing increasing amounts of ether toobtain the title compound as a clear oil. The proton and carbon NMR andinfrared spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₂₀ H₂₄ O₆ : %C, 66.7: %H, 6.71;

Found: %C, 66.2: %H, 6.56;

EXAMPLE 35 Preparation of 1-(2-Methoxymethoxycyclopropane.

A solution of 5.4 g (44 mmol) of thioanisole and 4.89 g (43.6 mmol) of1,4-diazabicyclo[2,2,2]octane in 44 ml of tetrahydrofuran was placed inan oven-dried flask and cooled to 0° C. A 2.5M solution of butyl lithiumin hexane (17.4 ml, 43.6 mmol) was added with stirring and the mixtureallowed to warm to room temperature and react for about 1 hour to formphenylthiomethyl lithium. A solution of 3.14 g (8.71 mmol) of1-(2-methoxymethoxyphenyl)-1-(3,4-dimethoxy-2-methoxymethoxyphenyl)ethenein tetrahydrofuran was added and the mixture heated to reflux withstirring under an argon atmosphere. After 10 hours another 21 8 mmol ofphenylthiomethyl lithium was prepared and added to the mixture andrefluxing was continued overnight. The mixture was then cooled andpoured into 200 ml of 5 percent aqueous sodium hypochlorite solution and200 g of ice and 150 ml of ether added. The organic phase was separated,dried over magnesium sulfate and concentrated by evaporation underreduced pressure to obtain 6.61 g of an oil. This was purified by silicagel chromatography (80 mm×3" filter funnel), eluting with hexanecontaining ever increasing amounts of ether to obtain 1.16 g of thetitle compound as an oil. The proton and carbon NMR and infrared spectrawere consistent with the assigned structure.

Elemental analysis:

Calc. for C₂₁ H₂₆ O₆ : %C, 67.4: %H, 7.00;

Found: %C, 65.8; %H, 6.46;

When an initial charge of 3.3 moles of phenylthiomethyl lithium per moleof olefin was employed, the product was1-(2-methoxymethoxyphenyl)-1-(4-hydroxy-3-methoxy-2-methoxymethoxyphenyl)cyclopropane,an oil obtained in 33 percent yield and identified by proton NMRspectroscopy.

EXAMPLE 36 Preparation of1-(2-Hydroxy-3,4-dimethoxyphenyl)-1-(2-hydroxyphenyl)cyclopropane.

A solution of 1.16 g (3.1 mmol) of1-(2-methoxymethoxyphenyl)-1-(3,4-dimethoxy-2-methoxymethoxyphenyl)cyclopropaneand 80 mg (0.47 mmol) of p-toluenesulfonic acid in 26 ml of methanol washeated at reflux with stirring for 2 hours under an argon atmosphere.The mixture was concentrated to half by evaporation under reducedpressure and 40 ml of ether was added. The resulting solution wasextracted with 30 ml of 5 percent aqueous sodium bicarbonate then 30 mlof water, dried over magnesium sulfate, and concentrated by evaporationunder reduced pressure to obtain 880 mg of the title compound as a foamyoil. The proton NMR spectrum was consistent with the assigned structure.

EXAMPLE 37 Preparation of Methyl3',4'-Dimethoxy-spiro(cyclopropane-1,12'(12'H)-dibenzo[d,g]]1,3]-dioxocin)-6'-carboxylate.

1-(2-Hydroxy-3,4-dimethoxyphenyl)-1-(2-hydroxyphenyl)cyclopropane wascondensed with dichloroacetic acid as in Example 3 to obtain the acid ofthe title compound in impure form. This was esterified with methanol bythe procedure of Example 4 to obtain a brown oil. This was purified byflash silica gel chromatography (25 mm×6"), eluting with hexanecontaining ever increasing amounts of ether to obtain the title compoundas a clear oil. The proton and carbon NMR and infrared spectra wereconsistent with the assigned structure.

Elemental analysis:

Calc. for C₁₄ H₁₈ O₄ : %C, 67.4; %H, 5.66;

Found: %C, 67.7: %H, 5.77;

EXAMPLE 38 Preparation of3',4'-Dimethoxyspiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylicAcid.

A solution of 76 mg (0.23 mmol) of methyl3',4'-dimethoxyspiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylatein 0.46 ml of tetrahydrofuran was combined with 0.172 ml (0.35 mmol) of2N aqueous sodium hydroxide and the mixture stirred for 1.3 hour. Theresulting mixture was diluted with 0.5 ml of water, extracted withether, and then acidified with 1N aqueous hydrochloric acid. Theresulting mixture was extracted 3 times with 1 ml portions of ether andthe combined ethereal extracts were dried over magnesium sulfate andconcentrated by evaporation under reduced pressure to obtain the titlecompound in quantitative yield as a white solid. The proton and carbonNMR and infrared spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₉ H₁₈ O₆ : %C, 66.7: %H, 5.30;

Found: %C, 67.2; %H, 5.04;

EXAMPLE 39 Preparation of(2-Methoxymethoxyphenyl)(2-methoxy-4-methylphenyl)methanol.

The general procedure of Example 31 was followed using2-methoxy-4-methylbenzaldehyde as the aldehyde. The title compound wasobtained as a yellow oil in 77 percent yield. The proton and carbon NMRand infrared spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₂₀ O₄ : %C, 70.9: %H, 6.99;

Found: %C, 70.8: %H, 6.75;

EXAMPLE 40 Preparation of2'-Methoxymethoxy-2-methoxy-4-methylbenzophenone.

The general procedure of Example 32 was followed using(2-methoxymethoxyphenyl)(2-methoxy-4-methylphenyl)methanol and theproduct purified by liquid chromatography in a similar manner to obtainthe title compound as an oil in 85 percent yield. The proton and carbonNMR and infrared spectra were consistent with the assigned structure.

Elemental analysis:

Calc. for C₁₇ H₁₈ O₄ : %C, 71.3: %H, 6.34;

Found: %C, 71.8: %H, 6.36;

EXAMPLE 41 Preparation of1-(2-Methoxymethoxy-phenyl)-1-(4-methyl-2-methoxyphenyl)ethene.

The general procedure of Example 33 was followed using2'-methoxymethoxy-2-methoxy-4-methylbenzophenone and the product waspurified similarly to obtain the title compound as a clear oil. Theproton and carbon NMR and infrared spectra were consistent with theassigned structure.

Elemental analysis:

Calc. for C₂₀ H₂₄ O₆ : %C, 76.0; %H, 7.09;

Found: %C, 73.4; %H, 7.32;

EXAMPLE 42 Preparation of1-(2-Methoxymethoxy-phenyl)-1-(4-methyl-2-methoxyphenyl)cyclopropane.

The general procedure of Example 34 was followed using1-(2-methoxymethoxyphenyl)-1-(4-methyl-2-methoxyphenyl)ethene and,initially, 3.3 moles of phenylthiomethyl lithium reagent per mole ofolefin. The title compound was obtained as a clear oil in 44 percentyield and its structure was verified by proton NMR spectroscopy.

EXAMPLE 43 Preparation of1-(2-Hydroxyphenyl)-1-(2-hydroxy-4-methylphenyl)cyclopropane.

A solution prepared from 490 mg (1.64 mmol) of1-(2-methoxymethoxyphenyl)-1-(2-methoxy-4-methylphenyl)cyclopropane and6.1 ml of a 1M solution (8.2 mmol) of bromodiethylborane indichloromethane was stirred overnight under an argon atmosphere. Ten mlof water were added, the phases were separated, and the aqueous phasewas extracted twice with 20 ml of dichloromethane. The combined organicextracts were dried over magnesium sulfate and concentrated byevaporation under reduced pressure to obtain1-(2-hydroxyphenyl)-1-(2-methoxy-4-methylphenyl)cyclopropane. The protonNMR spectrum was consistent with the assigned structure. This wasdissolved in 0.8 ml (8.2 mmol) of a 5M solution of bromodimethylboraneand allowed to stir overnight. Nothing happened. The mixture was cooledto 0° C. and 3.3 ml (3.3 mmol) of a 1M solution of boron tribromide wasadded with stirring under an argon atmosphere. After a short reactionperiod 2 ml of water was added and the mixture was extracted with 2 mlof 5 percent aqueous sodium bicarbonate then with 2 ml of water, driedover magnesium sulfate and concentrated by evaporation under reducedpressure to obtain 350 mg (84 percent of theory) of the title compoundas a foamy brown oil. The proton and carbon NMR spectra were consistentwith the assigned structure.

EXAMPLE 44 Preparation of Methyl3'-Melhylspiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6-carboxylate.

1-(2-Hydroxy-4-methylphenyl)-1-(2-hydroxyphenyl)cyclopropane wascondensed with dichloroacetic acid as in Example 3 to obtain the acid ofthe title compound in impure form. This was esterified with methanol bythe procedure of Example 4 to obtain a hemi-hydrate of the titlecompound. The proton and carbon NMR and infrared spectra were consistentwith the assigned structure.

Elemental analysis:

Calc. for C₁₉ H₁₈ O₄ ·1/2H₂ O: %C, 71.4: %H, 6.0l

Found: %C, 71.0: %H, 5.7;

EXAMPLE 45 Preparation of3'-Methylspiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylicAcid.

Methyl3'-methylspiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylatewas hydrolyzed by the method of Example 37 to obtain the title compoundas a white solid. The proton and carbon NMR spectra were consistent withthe assigned structure.

EXAMPLE 46 Postemergence Herbicidal Activity.

Compounds of the invention were dissolved in a mixture of 14 ml acetoneand 1 ml of dimethyl sulfoxide at one half of the most concentrateddesired application concentration and the resulting solution wascombined with 15 ml of an aqueous mixture containing about 20 percentisopropyl alcohol, about 2 percent Atplus 411F crop oil concentrate, andabout 0.04 percent Triton X-155® surfactant. Solutions containing lowerconcentrations were prepared by diluting this mixture with a solutioncontaining equal parts of a mixture of the second component describedabove and acetone containing 3 percent dimethyl sulfoxide. The solutionsof known concentration were sprayed evenly onto various greenhouse-grownplant species to obtain total coverage in approximately the 2-4 leafstage by means of a hand sprayer. The treated plants and control plantswere placed in a greenhouse and held under conditions conducive togrowth. After 13 days the percentage of control compared to theuntreated plants was determined visually. Representative compoundstested, application rates employed, plant species tested, and resultsare given in Table II. The control is stated on a scale of 0 to 100 with100 corresponding to complete kill and 0 to no effect. I n this test anapplication of about 100 ppm results in an application of about 260g/Ha.

                                      TABLE II                                    __________________________________________________________________________    POSTEMERGENCE CONTROL OF INDICATED SPECIES AT INDICATED DOSE RATES                                                     Wild             Yellow              Cpd Dose,                                                                             Coffee-                                                                           Cockle-                                                                            Jimson-   Morning-                                                                           Pig-                                                                              Velvet-                                                                            Buck-                                                                             Johnson-                                                                           Wild                                                                              Yellow                                                                            Nut-                No. ppm weed                                                                              bur  weed Lamium                                                                             glory                                                                              weed                                                                              leaf wheat                                                                             grass                                                                              Oats                                                                              Foxtail                                                                           sedge               __________________________________________________________________________     1  500 100 80   95   100  90   100 75   100 50   75  75  80                   3  500 100 90   100  90   80   100 40   85  50   80   0  70                   4  500 100 100  100  100  100  100 50   75  50   70  40  80                   8  500 100 100  100  85   90   85  100  90  70   70   0  50                  13  1000                                                                               50  0   50   --   40   50   0   60   0   --   0   0                  14  2000                                                                               50 60   50   --   70   60  20   35  45   --  30   0                  16  1000                                                                               95 30   90   --   30   70  100  40   0    0  45   0                  20  125 100 100  100  75   100  --  80   --  --   70  50  80                  21  62.5                                                                              100 100  85   --   90   70  60   30  60   75   0  80                  22  125 100 100  90   --   75   80  75    0  50   90  25  90                  23  250  90 100  100  95   85   95  85   50  75   90  45  80                  26  500 100 100  90   90   90   100 90   100 60   --   0  80                  27  2000                                                                               70 20   30   40   50   50  70   50   0    0   0  50                  29  1000                                                                              100 90   90   90   100  85  100  85  100  50   0  85                  31  250 100 95   100  --   85   80  100  90  100  --  60  75                  33  500  60 70   50   70   75   90  70   95  25    0  50   0                  35  2000                                                                               90 70   70   75   40   50  85   25  30    0  25   0                  44  250 100 80   90    0   50   50  80   50   0    0   0  60                  __________________________________________________________________________

EXAMPLE 47 Preemergence Herbicidal Activity.

Compounds of the invention were dissolved in 15 ml of acetone at onehalf of the most concentrated desired application concentration and theresulting solution was combined with an equal volume of water containing0.1 percent of Tween® 20 surfactant. Solutions containing lowerconcentrations were prepared by diluting this with additional aqueoussurfactant solution. The seeds of a number of species of plants wereplanted in beds containing a loam agricultural soil and, after planting,predetermined amounts of the herbicide mixtures were sprayed on the soilsurface and watered in to achieve the desired application rates. Theseand untreated control plants were then placed in a greenhouse underconditions conducive to germination and growth for a period of 14 daysat which time a visual assessment was made of the reduction in stand andgrowth for the treated plants as compared to the control plants.Representative compounds tested, application rates employed, plantspecies tested, and results are given in Table III. The control isstated on a scale of 0 to 100 with 100 corresponding to complete killand 0 to no effect.

                                      TABLE III                                   __________________________________________________________________________    PREEMERGENCE CONTROL OF INDICATED SPECIES AT INDICATED DOSE                   RATES                                                                                                                   Yellow                              Cpd                                                                              Dose,                                                                             Curly                                                                             Jimson                                                                             Morning-                                                                           Pig-                                                                             Velvet-                                                                            Cheat                                                                             Johnson-                                                                           Yellow                                                                            Nut-                                No.                                                                              lb/A                                                                              Dock                                                                              Weed glory                                                                              weed                                                                             leaf Grass                                                                             grass                                                                              Foxtail                                                                           sedge                               __________________________________________________________________________     1 4.0 25  90   60   85 80   70  --   40   95                                  4 2.0 --  85   75   100                                                                              80   95  50   40  100                                  8 1.0 100 90   90   100                                                                              90   95  88   55  100                                 19 0.25                                                                              90  90   95   90 95   60  97    0  100                                 20 0.25                                                                              85  90   90   85 50   75  85   35   85                                 22 0.25                                                                              90  95   95   95 70   95  90    0  100                                 25 0.25                                                                              80  80   93   95 93   70  80    0  100                                 29 0.50                                                                              90  99   85   90 90   90  88    0  100                                 __________________________________________________________________________

What is claimed is:
 1. A dibenzo[d,g][1,3]dioxocin-6-carboxylic acid compound of the formula ##STR12## wherein R¹ and R² together represent the fragment --CH₂ CH₂ --;R³ represents H or CH₃ ; and X, X', Y, Y', Z, and Z' each, independently represent H, F, Cl, Br, I, CN, NO₂, CO₂ H, NH₂, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenoxy, C₁ -C₄ alkylthio, phenylthio, C₁ -C₄ mono- or dialkylamino, (C₁ -C₃ alkyl)-carbonyl, phenylcarbonyl, C₁ -C₄ alkoxycarbonyl, or C₁ -C₄ mono- or dialkylaminocarbonyl, wherein each alkyl, alkoxy, and alkylthio group is optionally substituted with one or more compatible groups selected from C₁ -C₄ alkoxy, C₁ -C₄ alkylthio, F, Cl, Br, CN, and phenyl and wherein each phenyl group is optionally substituted with up to 3 groups selected from F, Cl, Br, CN, CF₃, C₁ -C₄ alkyl, and C₁ -C₄ alkoxy;and the agriculturally acceptable salt, esters and amides thereof.
 2. A compound of claim 1 wherein R³ represents hydrogen.
 3. A compound of claim 1 wherein X, X', Y, Y', Z, and Z' each independently represent H, F, Cl, Br, CH₃, OCH₃, SCH₃, CF₃, or OC₆ H₅.
 4. A compound of claim 1 wherein at least one of X and X' represents a designated substituent other than hydrogen.
 5. A compound of claim 3 wherein at least one of X and X' represents a designated substituent other than hydrogen.
 6. A compound of claim 1 wherein the compound is in the form of an agriculturally acceptable salt, ester, or amide.
 7. A compound of claim 6 wherein the compound is in the form of an agriculturally acceptable ester.
 8. A compound of claim 7 wherein the ester is a C₁ -C₈ alkyl or C₃ -C₈ alkenyl ester, each substituted with up to 3 groups selected from C₁ -C₄ alkoxy, F, Cl, Br, and phenyl, or a phenyl ester optionally substituted with up to 3 groups selected from F, Cl, Br, CH₃, or CF₃.
 9. A compound of claim 8 wherein the ester is a C₁ -C₄ alkyl ester.
 10. A compound of claim 9 wherein the ester is a methyl ester.
 11. A compound of claim 6 wherein the compound is in the form of an agriculturally acceptable salt.
 12. A compound of claim 11 wherein the compound is in the form of a sodium, potassium, ammonium, dimethylammonium, or triethylammonium salt.
 13. A compound of claim 5 wherein the compound is in the form of an agriculturally acceptable salt, ester, or amide.
 14. A compound of claim 5, spiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylic acid and its agriculturally acceptable esters, amides, and salts.
 15. A compound of claim 14, methyl spiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.
 16. A compound of claim 5, 4'-chlorospiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6-carboxylic acid and its agriculturally acceptable esters, amides, and salts.
 17. A compound of claim 16, methyl 4'-chloro-spiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]-dioxocin)-6'-carboxylate.
 18. A compound of claim 5, 4'-methylspiro-(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6-carboxylic acid and its agriculturally acceptable esters, amides, and salts.
 19. A compound of claim 18, methyl 4'-methylspiro(cyclopropane1,12'(12'H)-dibenzo[d,g][1,3]-dioxocin)-6'-carboxylate.
 20. An herbicidal composition comprising an agriculturally acceptable adjuvant or carrier and an herbicidally effective amount of a dibenzo[d,g][1,3]-dioxocin-6-carboxylic acid compound of the formula ##STR13## wherein R¹ and R² together represent the fragment --CH₂ CH₂ --;R³ represents H or CH₃ ; and X, X', Y, Y', Z, and Z' each, independently represent H, F, Cl, Br, I, CN, NO₂, CO₂ H, NH₂, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenoxy, C₁ -C₄ alkylthio, phenylthio, C₁ -C₄ mono- or dialkylamino, (C₁ -C₃ alkyl)carbonyl, phenylcarbonyl, C₂ -C₄ alkoxycarbonyl, or C₁ -C₄ mono- or dialkylaminocarbonyl, wherein each alkyl, alkoxy, and alkylthio group is optionally substituted with one or more compatible groups selected from C₁ -C₄ alkoxy, C₁ -C₄ alkylthio, F, Cl, Br, CN, and phenyl and wherein each phenyl group is optionally substituted with up to 3 groups selected from F, Cl, Br, CN, CF₃, C₁ -C₄ alkyl, and C₁ -C₄ alkoxy:and the agriculturally acceptable salt, esters and amides thereof.
 21. A composition of claim 20 wherein R³ represents hydrogen.
 22. A composition of claim 20 wherein X, X', Y, Y', Z, and Z' each independently represent H, F, Cl, Br, CH₃, OCH₃, SCH₃, CF₃, or OC₆ H₅.
 23. A composition of claim 20 wherein at least one of X and X' represents a designated substituent other than hydrogen.
 24. A composition of claim 21 wherein at least one of X and X' represents a designated substituent other than hydrogen.
 25. A composition of claim 20 wherein the compound is in the form of an agriculturally acceptable salt, ester, or amide.
 26. A composition of claim 25 wherein the compound is in the form of an agriculturally acceptable ester.
 27. A composition of claim 26 wherein the ester is a C₁ -C₈ alkyl or C₃ -C₈ alkenyl ester, each substituted with up to 3 groups selected from C₁ -C₄ alkoxy, F, Cl, Br, and phenyl, or a phenyl ester optionally substituted with up to 3 groups selected from F, Cl, Br, CH3, or CF₃.
 28. A composition of claim 27 wherein the ester is a C₁ -C₄ alkyl ester.
 29. A composition of claim 28 wherein the ester is a methyl ester.
 30. A composition of claim 25 wherein the compound is in the form of an agriculturally acceptable salt.
 31. A composition of claim 30 wherein the compound is in the form of the sodium, potassium, ammonium, dimethylammonium, or triethylammonium salt.
 32. A composition of claim 31 wherein the compound is in the form of an agriculturally acceptable salt, ester, or amide.
 33. A composition of claim 31 wherein the compound is spiro(cyclopropane-1,12'(12'H)-dibenzo [d,g][1,3]dioxocin)-6'-carboxylic acid or an agriculturally acceptable ester, amide, or salt.
 34. A composition of claim 33 wherein the compound is methyl spiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.
 35. A composition of claim 24 wherein the compound is 4'-chlorospiro(cyclopropane-1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylic acid or an agriculturally acceptable ester, amide, or salt thereof.
 36. A composition of claim 35 wherein the compound is methyl 4'-chlorospiro(cyclopropane-1,-12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6'-carboxylate.
 37. A composition of claim 24 wherein the compound is 4'-methylspiro(cyclopropane-1,12'(12H)dibenzo[d,g][1,3]dioxocin)-6'-carboxylic acid or an agriculturally acceptable ester, amide, or salt thereof.
 38. A composition of claim 36 wherein the compound is methyl 4'-methylspiro(cyclopropane1,12'(12'H)-dibenzo[d,g][1,3]dioxocin)-6,-carboxylate. 